Docs
Every section is also available as Markdown, for example /docs/getting-started.md.
Getting started
Install, allow screen access, take your first capture.
- Download the installer for your system from the Download page and open it.
- On the first launch Lass0 downloads its on-device model (about 2.5 GB) once. A progress bar shows it, and the file is checked against a SHA-256 fingerprint before it is used. Capture stays off, with a plain explanation, until that check passes.
- On macOS, allow Screen Recording when asked (see Permissions below).
- Press the capture shortcut, drag a region, and press Copy.
Lass0 lives in the menu bar (macOS) or system tray (Windows, Linux). The menu has Capture Text, Capture Same Area Again, Start Collect Session, Open Document, Open Lass0, Settings and Quit.
The four formats
Plain text, rich text, Markdown and Visual layout, and what each one does with headings, lists and tables.
Every capture is read once and turned into the same structure of blocks: headings, paragraphs, lists, tables, code and captions. Each format is a deterministic rendering of that structure, so the same capture always produces the same bytes. You can switch format in the result panel without capturing again.
| Format | Headings | Lists | Tables | Best for |
|---|---|---|---|---|
| Plain text | A line, then a blank line | - or 1. prefixes | Tab separated rows | Chat, search boxes, spreadsheets |
| Rich text | Real h1 to h3 | Real lists | Real table with header | Word processors, email, Notion |
| Markdown | # headings | - and 1. lists | Pipe tables | Notes, READMEs, issues |
| Visual | Placed where it sat | Bullets drawn | Box-drawing grid | Terminals, code comments, plain text email |
Rich text is written to the clipboard as HTML and plain text in one operation, so pasting into an app that takes only text still works. Visual is a monospace grid at most 100 columns wide; each line sits at the column its position on screen implies.
Shortcuts
Default capture and Collect shortcuts, and how to change them.
| Action | macOS | Windows and Linux |
|---|---|---|
| Capture a region | Cmd+Shift+G | Ctrl+Shift+G |
| Start a Collect session (Pro) | Cmd+Shift+Option+G | Ctrl+Shift+Alt+G |
| Cancel a selection | Esc | Esc |
Change the capture shortcut in Settings, then Shortcuts. If another app already uses the combination, Lass0 says so and keeps your old shortcut.
Timeline
Every capture, searchable, on your device.
The timeline lists captures newest first with a preview, format, time and word count. Search looks through the stored text. You can delete one capture or clear everything.
Lass0 stores each capture's structure and its plain text, never the image. Retention is yours to set: 7, 30, 90 days or forever. The history lives in a SQLite database in your app data folder and is never uploaded.
Free and Pro
- Free: the timeline is view-only. Copy and select controls are visible, disabled, and say why.
- Pro: copy any capture again, in any format, or tick several and press Copy N selected. Selected captures are joined with one blank line, in the order of the list.
Collect sessions
Capture several regions and copy them as one document (Pro).
- Press the Collect shortcut. Capture a region as usual.
- The Collect panel lists each region in the order you took it. Capture more, or remove one.
- Choose a format and press Copy all. You get one output with a blank line between regions.
- Done saves the session to your timeline; Cancel discards it.
On the free plan the Collect shortcut opens the upgrade panel and captures nothing.
Documents
Drop a PDF, Word, PowerPoint, Markdown, text or RTF file and copy its text in any format.
- Choose Open Document from the menu bar icon, or Read a document in the main window. A small window opens.
- Drop a file on it, or press Choose a file (Cmd+O on macOS, Ctrl+O elsewhere).
- Lass0 reads every page, sorts the text into headings, paragraphs, lists and tables, and copies it in your default format. Pick another format in the result to copy it again.
| Format | Files | How the structure is found |
|---|---|---|
| Sorted by the on-device model | ||
| Word | .docx | Read from the file |
| PowerPoint | .pptx | Read from the file |
| Markdown | .md, .markdown | Read from the file |
| Plain text | .txt, .text | Sorted by the on-device model |
| Rich text | .rtf | From the file, with the model for plain runs of text |
PDFs are read page by page. Pages with a text layer use it directly; pages that are only an image, such as a scan, go through the same on-device text recognition as a screen capture. Lines from consecutive pages are sorted together, so a table or list that crosses a page break comes out whole.
Accuracy comes before speed. The model checks its own grouping against the original lines; a part that fails is tried again and then split into smaller parts. If it still fails, nothing is copied and the window says which pages it could not lay out. A two page PDF takes under a minute on an Apple M1 Pro. Files up to 200 MB are accepted.
A document is saved to your timeline like a capture, under its file name, and counts against the same weekly allowance as a capture in that format.
If a document won't open
| Message | What to do |
|---|---|
| This is an older Office file | Open it in Word or PowerPoint and save it as .docx or .pptx. |
| This PDF is locked | Open it, save a copy without the password, and drop that. |
| No text in this document | The file has no text and no images of text. |
| Couldn't lay this out | The model's grouping failed its checks for the pages named. Nothing was copied. Try again; if it fails again, send feedback. |
Cleaners
Hide secrets and personal details, or rewrite text, before it reaches your clipboard.
Cleaners change the text after it is read and before it is copied. They work on captures, Collect sessions and documents. Turn them on in Settings, then Cleaning, or from the Clean button in any result. While a cleaner is on, the raw text is never copied first.
| Cleaner | What it does | Plan |
|---|---|---|
| Hide secrets | Passwords, API keys, tokens, private keys and connection strings become labelled blanks. | Pro |
| Hide personal details | Names, emails, phone numbers, addresses and ID numbers. The same person gets the same stand-in throughout. | Pro |
| Make it about any company | Names, customers, figures, dates and plans are swapped for generic ones. The story stays, the specifics go. | Pro |
| Sound less like AI | Rewrites stock phrases, em dashes and the even rhythm that machine-written text tends to have. | Pro |
| Reword | Changes at least one word in ten in every passage, keeping the meaning, names, numbers and terms. | Pro |
They run in this order: secrets, personal details, company, tone, reword. Secrets and personal details are found by rules on your device, such as key formats, card checksums and phone number shapes, and by the on-device model for names. The other three rewrite passages with the same model.
Every rewrite is checked. Names, numbers, code and links that should stay must still be there, a hidden value must not come back, and Reword must change at least one word in ten. A passage that fails is tried again. If it fails twice, nothing is copied and you can copy the original instead.
Both versions are kept. The result and the timeline have a Cleaned and Original switch, with a line saying what changed.
The rewrites come from a small model on your machine. The checks stop it dropping names, numbers and hidden values, but it can still pick a word that shifts the sense a little ("staging vault" became "development storage" in one of our test runs). Read the cleaned text before you share it.
Free limits and Pro
What the free plan allows each week and what Pro adds.
| Format | Free | Pro |
|---|---|---|
| Plain text | 100 a week | Unlimited |
| Rich text | 10 a week | Unlimited |
| Markdown | 10 a week | Unlimited |
| Visual layout | 1 a week | Unlimited |
Allowances reset every Monday at 00:00 local time. At the limit the result stays visible, nothing is copied, and the panel says so. Documents count as copies in the format you copy them in. Pro is $6 a month or $48 a year and adds copying from the timeline, multi-select copy, Collect sessions and the three cleaners that rewrite text.
Licence
After you subscribe, the key (GP-XXXX-XXXX-XXXX-XXXX) is emailed to you and shown on your account page. Open Settings, then Licence, paste the key and press Activate. One key works on up to 3 devices; remove a device from your account to free a place. Pro works offline for 14 days at a time and renews quietly when you are online.
Permissions and troubleshooting
Screen recording on macOS, Linux requirements and common messages.
macOS: Screen Recording
macOS lets an app read the screen only after you allow it. If it is off, the selection overlay shows 'Screen recording is off' with an Open System Settings button. Turn Lass0 on under Privacy and Security, then Screen Recording, and quit and reopen Lass0.
Linux
Text recognition uses Tesseract. The .deb package installs it; for the AppImage install the tesseract-ocr package from your distribution. On Wayland, the compositor may ask you to approve screen capture.
Messages
| Message | What it means |
|---|---|
| No text found in this selection | The engine found no readable text. Nothing was copied. Select a larger or sharper area. |
| Couldn't structure this capture. Nothing was copied. | The model's grouping failed its checks twice. Try again or capture a smaller region. |
| Model not installed | The first-run download has not finished or failed its check. Open Settings to retry. |
| Limit reached | You have used this week's allowance for that format. It resets Monday 00:00 local time. |